Cold Start Engine Noise

[umn]

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Porsche has no idea what they are doing with their oil recommnedations.

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Exactly. Maybe you should call them up and let them benefit from your knowledge.

Cheers,

Uwe

[1999Porsche911]

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Porsche has no idea what they are doing with their oil recommnedations.

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Exactly. Maybe you should call them up and let them benefit from your knowledge.

Cheers,

Uwe

They probably would benefit from someone elses knowledge. However, the primary reason for the confusion is that people DO NOT read correctly. Porsche DOES not recommend 0W40 in there engine at all times but simply state that it is approved and trhat it is the factory fill. As a matter of fact, below is an excerp from one of Porsches' TSB's.

Viscosity

The viscosity of an engine oil is specified by the SAE viscosity class. The first number and the letter W (winter) identify the viscosity at lower temperatures. For example: 0W or 5W, where 5W is more viscous than 0W. The second number indicates the viscosity at higher temperatures. For example: 40 or 50, where 40 is less viscous than 50. Multi-grade oils are identified by both viscosity specifications.

For example, SAF 0W40 or 5W40 or 5W50.

Examples:

0W40 and 5W40 oils have the same viscosity at higher temperatures, however, at lower temperatures, the SW oil is more viscous.

5W40 and 5W50 have the same viscosity at low temperatures, but at higher temperatures, the oil having viscosity class 40 is less viscous.

Temperature Ranges

Above -12°F. (-25°C): all oils approved by Porsche for the vehicle type to be considered Below -12°F (-25°C:: all oils approved by Porsche for the vehicle type to be considered which have the SAE class 0W at lower temperatures.

Keep using the 0W40 in hot climates and we'll continue this conversation when your valve guides wear out along with the main crank bearings.

So why the sudden change in "approved" oils?. Why was the factory fill for the 3.4 engine 15W50, yet some say you HAVE to use 0W40 now? Did the engine internals change? Did Porsche originaly make a mistake? Is the "approved" list compiled of the biggest contibutors? There is NO benefit, whatsopever for using 0W40 versus 5W50 or 15W50 when you are in temperatures above 20F. This is not conjecture, but fact. There ARE, however. substantial benefits for using 5W50 or 15W50, which incude less shearing at high engine temperatures, longer adhesion to engine components, less evaporation, less oil usage (for those of you who are burning oil). Even Mobil 1 says that the 15W50 is a great oil:

Mobil 1 15W-50 is our most advanced performance synthetic engine oil designed to provide ultimate wear protection for a smooth driving experience every time. Mobil 1 15W-50, Performance Driving Formula, exceeds the requirements of the industry and car manufacturers' standards required for high-performance turbo-charged, supercharged gasoline and diesel multi-valve fuel injected engines. Mobil 1 15W-50 is a winning race proven technology. It is especially suited for high-speed highway, towing, and other severe service situation. Mobil 1 15W-50, Performance Driving Formula, provides extra engine oil performance and protection for the winning edge. Mobil oils are the official oils of NASCAR.

So, unless you can somehow make a 0W40 oil protect my engine better than a 15W50 oil at engine temperatures above 230F, I think I'll stick with my uneducated and ignorant decision to use 15W50.

[nycebo]

So, unless you can somehow make a 0W40 oil protect my engine better than a 15W50 oil at engine temperatures above 230F, I think I'll stick with my uneducated and ignorant decision to use 15W50.

Great post. Given that Mobile doesn't make a 5W50 motor oil, do you think that Castrol is still very reputable? Since it does get pretty cold up here this time of year, I'd feel more comfortable using at least a 5W, particularly if I make weekend ski runs up to Vermont where it can get very very very very cold (I've skied in -25 degree F weather). Thanks.

[1999Porsche911]

So, unless you can somehow make a 0W40 oil protect my engine better than a 15W50 oil at engine temperatures above 230F, I think I'll stick with my uneducated and ignorant decision to use 15W50.

Great post. Given that Mobile doesn't make a 5W50 motor oil, do you think that Castrol is still very reputable? Since it does get pretty cold up here this time of year, I'd feel more comfortable using at least a 5W, particularly if I make weekend ski runs up to Vermont where it can get very very very very cold (I've skied in -25 degree F weather). Thanks.

I run either Castrol or Mobil. Both are good oils.

[911h20]

The Mobile website recommends 0W-40 for the 3.4L. Interesting. http://www.mobiloil.com/usa-english/motoro...s.aspx?option=2

[Gabo2k]

The Mobile website recommends 0W-40 for the 3.4L. Interesting. http://www.mobiloil.com/usa-english/motoro...s.aspx?option=2

I don't think this link is accurate at all in that it does not take ambient temperature into consideration.

What this says is that someone in Alaska can use the same weight oil as someone in the Sahara desert.

Now, if they asked for your zip code or city of residence, then it would be different.

They are basically quoting factory fill...

[Tool Pants]

An old oil debate comes back to life. To add to the obsession, if you have recently used Mobil 1, is the effects of Katrina. :huh: You might be using the "hurrican blend."

Mobil was unable to supply one of the additives in the normal Mobil 1 formulation due to Katrina, so another additive was subsituted. Inventories of the "substitute" oil are still floating around.

I'm about due for an oil change and don't want to put in the hurrican blend crap. I want pre-Katrina spec oil for my Boxster.

Nothing but the best for my Boxstir....